Folding drawing-board



T. W. .IARDINE. FOLDING DRAWING BOARD. Armcmou r1150 luLvzo. 1911.

" Patentbd Mar. 15, 1921.

2 SHEETSSHEET I T. W. JARDINE. FOLDING DRAWING BOARD. APPucmpn map mum-.1912.

Patented Mar. 15, 1921.

2 SHEETSSHEET 2.

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,4 TTORNEV UNITED STATES THOMAS W. JARDIN'E, OF ENGLEW'OOD, NEW JERSEY.

FOLDING DRAWING-BOARD.

Application filed July 20, 1917.

To alt whom it may, concern.

Be it known that I, THOMAS W. J ARDINE, a citizen of the United States, residing at Englewcod, in the county of Bergen and State of New Jersey, have invented certain new and useful Improvements in Folding Drawing-Boards, of which the following is a specification, referring to the accompanying drawings, forming part thereof.

This invention is an improvement in folding drawing boards. Its object is to provide alight drawing board which can be folded up in compact form for facility of transportation and storage.

igure 1 isan end elevation of the drawing board in position for use;

Fig. 2 is a front elevation thereof;

is an end elevation of the framework of the device folded up;

Fig. at is a front elevation thereof;

Fig. 5 is an enlarged detail longitudinal view of one of the locking joints of the folding stays or braces;

Fig. 6 is a transverse section thereof on the plane 6-6 of Fig. 5;

. Fig. 7 is an enlarged end view of the hinged slats which together constitute the board proper;

Fig. 8 is an enlarged horizontal section, taken in the middle plane of the board proper and stiffening traverse, and showing the locking means for securing the traverse in position;

Fig. 9 is a correspondingly enlarged view, taken on the plane 9 of Fig. 8;

Fig. 10 is an enlarged end elevation of the adjustable connection between the folding frame and the horizontal bar or bracket which carries the board proper, and

. 11 is a correspondingly enlarged frontelevation of said. adjustable connection.

The folding frame or standard comprises two A-frames 12, each having its two legs pivoted at their apex to the hub 13., formed on the cross-bar or bracket 14 at either end of the board proper. Each A-frame comprises a folding brace 1516 connecting the two legs at an elevation near their lower ends. The bars 1516 of this folding brace are pivoted to respective lugs onthe legs 12 and are pivotally connected together in the self-locking joint. particularly illustrated in Figs. 5 and 6. The bar 16 has a concave channel and the bar 15 has corresponding convex surface. The bars are pivoted together by the bolt 17 and a spring 18 is com- Specification of Letters Patent.

Patented Mar. 15, 1921. Serial No. 181,697.

pressed between its nut 19 the spring receiving recess in the bar 16, so that when the bars are orought into alinement the spring will snap the convex surface of the bar 15 into the concave recess of the bar 16 so as to lock the bars in'rigid alinement. i

' The A-franies are spaced apart by foih horizontal folding stays or braces, each consisting in bars 20 and 21 pivoted to suitable lugs on the A-frames and pivoted together by the self-locking joint above described. The opposite Aframes are also similarly connected by two diagonal folding stays or braces, each consistingin a long bar 22. and a short bar 23 pivoted together by the aforesaid self-locking joint and at their opposite ends pivoted to the opposite A-framesI The hub 13 of each bracket l i'has a serrated surface 33 on one side which co-acts with a corresponding serrated surface on one of the legs 12 of the A-frame which supports the bracket, so that by the meshing of these serrations the hub of the bracket may be firmly gripped in any desired angular position between the ends of the legs 12, whereby the drawing board may be adjustably tilted. Each bracket 14 is provided with dowels 2e projecting from its upper surface and entering corresponding holes in the board proper, which is composed of straight slats 25. hinged together by suitable hinges and the bottom of 26 on the underside of the board so that when the board is lifted from the brackets 14 it may be rolled up by bending these hinges. A flush and rigid alinement of the slats is insured by the semi-circular rib-andgroove union 27 in which their contiguous .ges are united when the hinges are straightened out. The ends of the slats are cut with a continuous slot 28 which receives the tongue 29 of the stiffening traverse 30.

which has a straight outer edge adapted to the head of a Tsquare. Preferably each end of the board is provided with one of these stiffening traverses which, together with the rib-and-groove unions between the inclividual slats. insures the effect of a rigid, flat board.

Each traverse is locked to the board at either end of the traverse by the locking connection shown in Figs. 8 and 9. The traverse is bored with a transverse hole 31., in the outer end of which is secured the bushing 35. The collar 36 is threaded on the lockstem 32 and slides in the bore 31.

and when the traverse is detached from the board, the outer end of this collar is held head 38 which fits flush in the slot in the plate 39, when the spring 37 is thus expanded, A duplicate loz'k-plate 4-0 is set flush in the bottom of the groove 28 in, one

of the slats 25 which has counter re -H s 41 to make room for the locking heed when it is pushed through the slot in tl e lock-plate and turned ninety degrees to bridge the slot and bear on the inner surface of the lock-plate, which is done by means of the removable key fitting over the squared outer end of the lock-stem.

When the board is to be folded, the two traverses 30 may be placed beside the frail. after'folding, as shown in Figs. 3 and 4, and the board proper may then be rolled around the parcel. V

The generic invention may be embodied in different species of construction within the principles and scope of the following claims:

1. A folding drawing board comprising slats hinged together edge to edge a stiff fening traverse adapted to be connected with the slats, and locking means adapted to secure said traverse in positionand including springs arranged to press the traverse against the slats. I

2. A- folding drawing board comprising slats hinged together edge to edge, a stiffening traverse adapted to engage the ends of 4. A folding drawing board comprising a plurality of slats hinged together and provided at their. ends with slots registering with each other when the corresponding faces of the slats are presented in a bornmon plane, a stiffening traverse adapted to be reinovably seated in the slots formed the slat ends, and resilient means for retaining the stifiening traverse in the slots and in firm contact with the slat ends;

In testimony whereof I have affixed my signature. 7 s

g THOMAS W. JARDINE.

Witness: 7

EMILE A. RrrzLnR, 

